Electromagnetic relay



, P 1929- J. ERIcKsQN 1,727,968

ELECTROMAGNET I C RELAY Original Filed Dec. 31. 1919 l uuen lnr Jul'm Ericksun Patented Sept. 10, 1929.

UNITED STATES PATENT OFFICE.

JOHN ERICKSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO AUTOMATIC ELECTRIC INC., OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE.

ELECTROMAGNETIC RELAY.

Original applications filed December 31, 1919, Serial No. 348,548, and September 11, 1925, Serial No; 55,688.

- Divided and this application filed October 26, 1926. Serial No. 144,266.

My invention relates in general to electromagnetic relays and has for its object the provision of a relay having a variable time constant; and more especially, a relay having a variable time constant which is adjustable between much wider limits than are the well known types of slow acting relays now in common use. The preferred means used to attain this and other useful objects will be described fully hereinafter, reference being had to the accompanying drawing. It may be further pointed out that this application is a division of a co-pending application Serial No. 348,548, filed December 31, 1919,

now Patent No. 1,641,256, issued September 6, 1927 and of application Serial No. 55,688 filed Sept. 11, 1925.

The drawing shows a relay of my improved type connected for use in combination with a diiierential relay to hold a circuit open for a certain definite time interval.

The purpose of the embodiment of the invention as shown is to produce a prolonged opening of the circuit extending over con- 2 ductor 20 whenever the relay 10 is energized.

The operation is as follows: When the circuit of relay 10 is closed at contact devices 21 it attracts its armature and closes contact springs 12 and 13. By this operation a circuit is completed through the two windings of the differential relay 11 in parallel. The circuit for one of the windings, however, includes the contact springs 14 and 15 and is rapidly interrupted by vibrations of the weight 17 When relay 10 is first energized, therefore, the differential relay 11 is unbalanced and is operated to attract its armature and separate contact springs 18 and 19. As soon as the weight 17 has ceased vibrating contact springs 14: and 15 remain closed and the circuit through both its windings being now closed continuously, difi'erential relay 11 will retract its armature and again close contact springs 18 and 19. Regulation of the time interval of the differential relay is accomplished by adjusting the weight 17 on rod 16, and by regulating the length of stroke of the armature of relay 10.

In adjusting the relays wide adjustments 5 of the time constant is accomplished by regulating the strokeof the relay armature. The adjustment of the weight by moving it up and down changes the frequency of the vibrations and while it alters to some extent the durationof a series of Vibrations it is:- of use chiefly in, adjusting the frequency to the natural period of the device which has to be operated.

Having described my invention what I desire to have secured and protected by Let-: ters Patent will be pointed out in the appended claims.

What is claimed is:

1. A relay comprising a winding having a core extending there through, an armature cooperating with said core, a pair of contacts operated by the movement of said armature, a flexible reed secured to the armature vibrating responsive to an actuation of the armature and having movement independent of the armature, a second pair of contacts associated with and operated by the movement of said reed, and a weight adjustably secured to said reed.

2. A relay comprising a winding having 175 a magnetic core, an armature cooperating with said core, a pair of normally open contact springs lying in a plane parallel to said core adapted to be maintained closed during the entire time the armature is attracted, a second pair of contact springs secured to said armature and a weighted member connected to one spring of the second pair set in motion by said weighted mem- 185 ber when the armature is attracted to cause relative movement between the second pair of contact springs.

3. An electromagnetic relay having an armature adapted to be attracted when the magnet is energized and retracted when the magnet is deenergized, a weight connected to said armature and set in motion when the armature is attracted, the said connection being flexible so that the weight is enabled to continue its movement after the movement of the armature has ceased and thereby oppose retraction of the armature when the magnet is deenergized, a pair of contact springs actuated by the movement of said 1.19

Weight, and a second pair of contacts actuated by said armature.

4. An electromagnetic relay having an armature adapted to be attracted when the magnet is energized and retracted when the magnet is deenergized, an inertia member associated with said armature, a flexible connection between the armature and said member whereby the said member is set in motion When the armature is attracted and whereby the inertia of said member delays the retraction of the armature in case the deenergiz'ation of the magnet occurs Within a predetermined time, a pair of contacts also influenced by said inertia member and a sec- 0nd pair of contacts controlled b the operation of said armature as modi ed by said member.

In witness whereof, I hereunto subscribe my name this 25th day of October, A. D.

JOHN ERICKSON. 

